The reason why GIA should add the SI3 grade

[John P]

I have no reason whatsoever to doubt my friend John's experience looking at crystals. In general, cutting round diamonds is a different ball of wax than cutting fancies- and even more so if one needs to buy crystals for super ideal RBC's. So we will see this from different perspectives.

Very true. Upstream we see it all...well, mostly. More on that below. What you ladies and gentlemen see downstream reflects Bryan's comments about polarization. At the top of the chain we now reject rough at a higher rate, as @blueMA referenced. But the story doesn't end there. Even the most egregious GQ rough has value, so it's going to trickle through production and polish somewhere in the world. Where does it go after that? Not to NYC. That's a sharp market with savvy traders so @Rockdiamond lives in something of a protectorate against this. He's even one of the guards. Likewise, suppliers won't waste expense sending them to organizations who kick them back. And companies like @Texas Leaguer's have built relationships and reputations, which makes them a non-destination. This means that many remain with producer/suppliers. That's one reason you see diamonds at the bottom of virtual warehouse listings for 50% less with reports that are years old. It's also why @Garry H (Cut Nut) experiences this with more frequency. Oz is a less seasoned marketplace than the USA, and they're in closer proximity to India and China, which are ground zero for this stuff.

I just think the reason that is true probably has more to do with changes in the marketplace than lab grading trends or the quality of rough coming out of the ground.

I'm with you most of the way Bryan. As it relates to greater scrutiny as a blanket you make great points. But when it comes to gem-quality in trading centers I'm afraid your diamond mines in Houston spoil you. In addition to the general underground trend there's a Marange component that can't find daylight in Antwerp (with dubious exceptions) but pours freely into IN & CN.

 

[Diamond Girl 21]

what

"Spot on. But what lies beyond 10X?"(John's quote) Sorry, I couldn't get this to work properly.

All the mysterious fun stuff! But as far as grading, anything beyond 10X doesn't count. Higher magnification is only used to make more specific identification. For example, to help you see if a feather is breaching the surface or if an interesting inclusion could be further identified. But I'm sure you know this info better than I. I would definitely defer to you and the other experts. I love learning from all of you.

 

[John P]

All the mysterious fun stuff! But as far as grading, anything beyond 10X doesn't count. Higher magnification is only used to make more specific identification. For example, to help you see if a feather is breaching the surface or if an interesting inclusion could be further identified. But I'm sure you know this info better than I. I would definitely defer to you and the other experts. I love learning from all of you.

Copy that, and I agree entirely. "Stuff" beyond 10X is not relevant to the main topic of this thread. There's some cross pollination between current clarity topics (I'm thinking of this thread specifically) which inspired the mention here. Thank you for the reset.